Identifying patients with cancer who are most at risk for VTE is essential to better target thromboprophylaxis, with the eventual goal of reducing the burden as well as the consequences of VTE for patients with cancer.

BACKGROUND: Recent studies suggest that thromboprophylaxis is beneficial in preventing venous thromboembolism (VTE) in cancer outpatients, but this is not widely adopted because of incomplete understanding of the contemporary incidence of VTE and concerns about bleeding. Therefore, the authors examined the incidence and predictors of VTE in ambulatory patients with bladder, colorectal, lung, ovary, pancreas, or gastric cancers. METHODS: Data were extracted from a large health care claims database of commercially insured patients in the United States between 2004 and 2009. Demographic and clinical characteristics of the cancer cohort (N ¼ 17,284) and an age/sex-matched, noncancer control cohort were evaluated. VTE incidence was recorded during a 3-month to 12-month follow-up period after the initiation of chemotherapy. Multivariate analyses were conducted to identify independent predictors of VTE and bleeding. RESULTS: The mean age of the study population was 64 years, and 51% of patients were women. VTE occurred in 12.6% of the cancer cohort (n ¼ 2170) over 12 months after the initiation of chemotherapy versus 1.4% of controls (n ¼ 237; P < .0001); incidence ranged by cancer type from 19.2% (pancreatic cancer) to 8.2% (bladder cancer). Predictors of VTE included type of cancer, comorbidities (Charlson Comorbidity Index score or obesity), and commonly used specific antineoplastic or supportive care agents (cisplatin, bevacizumab, and erythropoietin). CONCLUSIONS: This large, contemporary, real-world analysis confirmed high rates of VTE in select patients with solid tumors and suggested that the incidence of VTE is high in the real-world setting. Awareness of the benefits of targeted thromboprophylaxis may result in a clinically significant reduction in the burden of VTE in this population. Cancer 2013;119:648-55.

Background Leukocytosis has been associated with thrombosis and mortality in cancer patients. We explored the association of leukocytosis with venous thromboembolism (VTE) and early mortality in cancer patients initiating chemotherapy. Methods Data from a prospective, multicenter observational study of treatment-related complications in 4,405 ambulatory cancer patients initiating chemotherapy was used for this analysis. The association of leukocytosis, VTE and mortality during the course of chemotherapy was evaluated in univariate and multivariate analysis. Results Ninety-three patients (2.1%) developed VTE and 134 (3%) died over a median follow up of 75 days (range 0–384). Of 4391 patients with available baseline white blood cell (WBC) count, 561 (12.8%) had elevated pretreatment leukocyte counts, defined as WBC > 11×109 cells/L. VTE occurred in 25 of 561 patients (4.5%) with baseline leukocytosis compared to 68 of 3830 (1.8%) with WBC ≤ 11×109 cells/L (P<0.0001). Baseline leukocytosis was associated with VTE by multivariate analysis as well (HR 2.1, 95% confidence interval 1.3–3.4, p=0.003). Forty one patients (7.3%) with leukocytosis died compared to 92 (2.4%) with WBC ≤ 11×109 cells/L (P<0.0001). Baseline leukocytosis was associated with early mortality by multivariate analysis as well (HR 2.2, 95% confidence interval 1.5–3.3, p<0.0001). Mortality was greatest in patients with both leukocytosis and VTE. In multivariate analysis several factors were predictive of leukocytosis. Conclusions Elevated WBC, particularly neutrophils, is strongly associated with increased risk of VTE and mortality in cancer patients receiving systemic chemotherapy. Further studies are needed to elicit the mechanisms involved.

BackgroundThis study examines venous thromboembolism (VTE)-associated resource utilization and real-world costs in ambulatory patients initiating chemotherapy for selected common high-risk solid tumors.MethodsHealth care claims data (2004–2009) from the IMS/PharMetrics® Patient-Centric database were collected for propensity score-matched adult cancer (lung, colorectal, pancreatic, gastric, bladder, or ovarian) patients initiating chemotherapy with VTE (n = 912) and without VTE (n = 2736). Health care resource utilization (inpatient, outpatient, and outpatient prescription drug claims) and costs were compared between the two cohorts during the 12-month follow-up period after the index VTE event. Incremental costs were adjusted for demographic and clinical covariates.ResultsCancer patients with VTE had approximately three times as many all-cause hospitalizations (mean 1.38 versus 0.55 per patient) and days in hospital (10.19 versus 3.37), and more outpatient claims (331 versus 206) than cancer patients without VTE (all P < 0.0001). Cancer patients with VTE incurred higher overall all-cause inpatient costs (mean USD 21,299 versus USD 7459 per patient), outpatient costs (USD 53,660 versus USD 34,232 per patient), and total health care costs (USD 74,959 versus USD 41,691 per patient) than cancer patients without VTE (all P < 0.0001). Total mean VTE-related health care costs were USD 9247 per patient over 12 months. Adjusted mean incremental all-cause health care costs of VTE were USD 30,538 per patient for cancer overall, ranging from USD 11,946 for gastric to USD 38,983 for pancreatic cancer.Conclusion:VTE is associated with significant inpatient and outpatient resource utilization, and increased all-cause (in addition to VTE-related) health care costs among ambulatory cancer patients. Measures to prevent outpatient cancer-associated VTE may reduce health care utilization and costs in this population.